Date: Thu, 20 Nov 2003 22:19:32 -0500 From: "Brian F. Feldman" <green@FreeBSD.org> To: current@FreeBSD.org Cc: Ian Dowse <iedowse@maths.tcd.ie> Subject: Re: kernel panic trying to utilize a da(4)/umass(4) device with ohci(4) Message-ID: <200311210319.hAL3JWdX001551@green.bikeshed.org> In-Reply-To: Message from "Brian F. Feldman" <green@FreeBSD.org> of "Thu, 20 Nov 2003 22:09:33 EST."
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"Brian F. Feldman" <green@FreeBSD.org> wrote: > Thanks for the patches to try! They unfortunately didn't fix the crash I > have, but I found out why it's occurring. > > See ohci.c:1389: > if (std->td.td_cbp != 0) > len -= le32toh(std->td.td_be) - > le32toh(std->td.td_cbp) + 1; > > In one of my transfers (look in my log for the 2560 byte one) that statement > actually adds 8192 to len, which is utterly bogus because you can see it > only allocates 2560 -- hence when it tries to finish the transfer it > memcpy()'s way too much memory and my kernel segfaults. If I #if 0 this out, > I'm left only with "umass0: BBB reset failed, STALLED" messages... which is > a lot better than before! I don't know under what situations that bit of > code makes sense, but it definitely needs more reviewing! > > Please check out my debugging messages and tell me if you see any hints as > to why the transfers are getting stalled. I should have looked at the > debugging messages long ago, I guess. Thanks! > > http://green.homeunix.org/~green/ohci-debugging.txt.gz BTW, replying to myself -- it seems to be something missing from the multi-allocation transfers (>8KB), because I can do up to 8KB transfers perfectly fine now, but 10KB ones, for example, like mdir(8) does are the ones that give me BBB stalls. -- Brian Fundakowski Feldman \'[ FreeBSD ]''''''''''\ <> green@FreeBSD.org \ The Power to Serve! \ Opinions expressed are my own. \,,,,,,,,,,,,,,,,,,,,,,\
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